I. Field of the Invention
Embodiments of the present invention relate to devices for removing materials from the ground. Particularly, embodiments of the present invention relate to post pullers. More particularly, embodiments of the present invention relate to post pullers operated by and/or controlled by powered vehicles.
II. Discussion of Related Art
There are countless applications for a grasping and lifting apparatus for heavy or awkward work pieces. One example is a post puller grasping an elongated object such as a fence post or a telephone pole and lifting it out of a post hole or positioning it in a post hole or simply moving it about from place to place. A typical post puller consists of some type of clamp attached to a machine with lifting power, for example a tractor or a skid-steer loader. The clamp may be nothing more complex than a length of heavy chain wrapped tightly around the post, securing the post to the lifting machine. Such a clamp enables a remotely located worker such as a farmer with no power machinery other than a tractor to use the power lifting capacity of the tractor to place and remove fence posts or other awkward or heavy objects including brush and trees.
A chain used as a clamp may require a person to hold the chain securely around the post during the lifting and moving operation. If the chain is attached to a tractor with lifting capability, it may be possible for one person to simultaneously hold the chain and operate the tractor, but at best this is clumsy, and it often poses safety issues, so a second person may be needed. Lifting machines such as tractors or skid-steer loaders generally lift by pivoting about a point, and this results in the lifting motion being arcuate rather than linear. When inserting a post into, or removing it from, a deep post hole, an arcuate lifting motion can cause the post to bind against the walls of the hole, damaging the hole or the post, or rendering the lifting operation impossible.
Accordingly, there has been a need for a lifting apparatus easily attached to a lifting machine in a remote location, safely and conveniently operated by a sole worker, and can lift clumsy or heavy objects. It would be desirable for such an apparatus to lift an object through a linear rather than an arcuate range of motion.